Stair.



P. A. WINSLOW.

STAIR.

APPLIUATION FILED NOV.20,1909.

Patented Bea-9, 1913.

TLOSM'EW F m n E v U 1 Fri ru: I5 A.Wm51uw WITI'LE '5 E 5 @MK; QM M): jyab film FEE 5 FRANCIS A. WINSLOW, OF CHICAGO, ILLINOIS.

STAIR.

ins ore.

Specification of Letters Patent.

Patented Dec. 9,1913.

Application filed November 20, 1909. Serial No. 529,033.

To all whom it may concern."

Be it known that I, FRANCIS A. W'msnow, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Stairs, (Case 8,) of which the following is a full, clear, concise, and exact description, reference being bad tothe accompanying drawings, forming a part of this specification.

My invention relates to stairs, more particularly to concrete structures of that kind.

The general object of stair construction, in addition to rigidity and durability, is the provision of afire-proof way and, consistent with thesepurposes, my invention has further objects in simplicity of manufacture and assembly and in the provision of a stair which will be pleasing to the eye. To this end I propose previously forming a unit comprising atread and a riser of concrete, tutti-colori, or other cementitious material, and then subsequently setting up these units in a suitable casing.

My invention also contemplates the employment of reinforcing means for the cementitious unit, for the purpose of durability, and proposes a practical manner of reinforcing the unit whereby the particular strains to which such a member would be subjected are effectively counteracted.

One of the features of my invention resides in the fact that the joint between successive steps will be invisible. To secure this desirable result I form the riser of the unit at the rear of the step portion, so that it maylform the riser portion of the upwardly succeeding step, and provide a nosing at the forward end of the tread portion which extends and looks over the preceding riser to form a mechanically resistant connection.

I contemplate the use of such a stair as has been broadly described, with or without the use of a soifit. In the former case the particular appearance of the under sides of the units is comparatively unimportant, but, in the latter case, I propose a design or conformation which will be of good appearance when the units are assembled to form a way. By this previous formation or molding of the stair units they can be made with greater care and with more uniformity and, further, the accuracy thus obtained will be of advantage in assembling the structure.

My invention is of further importance in that, although composed almost entirely of cement, the structure is light and may be easily handled in construction and assembly.

By my invention as above outlined all the well-known advantages of concrete con struction are retained in the advantageous practice of previous forming and subsequent assembly, while the more specific features toward which my invent-ion is directed insure the provision of a neat appearing, well constructed, fireproof stair.

My invention is embodied in the structure illustrated in the accompanying drawi ng, in which Figure l is a longitudinal sectional view illustrating the use of my invention with a solfit; Fig. 2 is a similar view illustrating the use of my invention without a soilit; and Fig. 3 is a sectional view taken on the plane 33 of Fig. 1, the line ar-w of this figure showing the plane of section of the other two figures. 7

In the above drawing I have illustrated the members 4, 4, in the form of iron plates, which go to form the side plates of the stair casing. In Fig. 3, one of these plates is shown as an ordinary. channel beam supported against a Wall 5, while the other member is shown as a casing which is exposed to the eye and is, therefore, provided with any decorative forms which may be desired. Besides being supported against a wall or in some other suitable manner, these side plates are conveniently held together by means of a series of connecting bars 6, which include the turn buckle 7. These bars will be further referred to hereinafter. The side plates 4, 4 are provided at the bottom edges thereof with the inwardly extending flanges 8, 8, which support primarily either the soifit as shown in Fig. 1 or the stair sections directly, as shown in Fig. 2. Referring to the form shown in Fig. 1, the soffit is shown at 9, and is conveniently formed of a series of plates or slabs formed of concrete, tutti-colori orother cementitious material. In this figure I have shown a gangof about four steps, the gang being made up of a number of units each of which comprises a tread portion 10, a riser por tion,11 and an overhanging nosing 12 at the front edge of the tread. This unit is constructed of concrete, tutti-colori, or other cementitious material, and is primarily molded as a complete structure before a of them are assembled to form a stair-way. The riser 11 extends downwardly below the tread portion 10, as indicated at 13, and is there provided with one or more reinforcing rods 14, which, as shown in Fig. 3, are in the-form of truss bars. These truss bars efi'ectively counteract the tendency of the strains imposed upon the unit to crack the same longitudinally relative to the way. The portion 13 may be made of such size as to accommodate any number of bars which are deemed necessary. The upper edge of the riser 11 is widened as indicated at 14, this widened portion having the transversely extending groove or pocket 15 in which the corresponding connecting bar or tie rod 6, previously referred to, may be disposed, as indicated clearly in the various figures. The bottom face of the extension 13 of the riser is made to correspond with the number incline of the soiiit so that the various parts of the complete stair are disposed to good advantage to obtain effective mechanical connection.

In building up a stair-way, it is convenient to put the lowermost unit in place after the corresponding tie rod has been inserted between the side plates and then to actuate the turn buckle to bring the parts together. The next upwardly succeeding unit is then put in place, the nosing 12 thereof extending over the preceding riser 11. It is apparent from Fig. 1 that the joint between the two units will not be apparent to the eye. If desired the joint between the stair sections may be cemented to make a water-proof joint and to assist in retaining the parts in proper position. In Fig. 2, wherein the soifit is dispensed with, the under sides of the units are conformed to present a pleasing appearance. In this modification, the bottom faces of the extensions 13 are preferably made horizontal, as shown, the ends thereof being extended downwardly as shown at 16 to engage the flanges 8 in face to face relation as was described relative to the engagement between the extension 13 and the soflit 9 in the other form of my invention.

I claim as new and desire to secure by Letters Patent:

1. A previously formed stair unit formed of cementitious material and comprising a tread and-a riser at the rear edge of said tread, said riser extending both above and below said tread, and truss shaped reinforcing rods disposed in the downwardly extending part of said riser.

2. A stair comprising a gang of units previously formed of cementitious material, each of said units comprising a tread, a riser at the rear edge of said tread, said riser extending both above and below said tread, a depending nosing at the forward edge of said tread for looking over the preceding riser, and reinforcing rods in the downwardly extending portion of said riser.

3. A stair comprising a pair of side plates, and a gang of cementitious units each comprising a tread and a riser, each riser having a transverse groove in the top thereof, and a tie rod lying in said groove and secured between said side plates.

1. In a stair, an oblique support, and a gang of units previously formed of cementitious material resting on said oblique support, each of said units consisting of a tread, a riser at the rear edge of said tread, and a depending nosing at the forward edge of said tread, the forward edge of said tread resting on the preceding riser, the depending nosing locking over it, a plate on each side of said gang of units, and a series of tie rods connecting said plates, each of said tie rods being disposed in a transverse groove in the top of one of said risers.

In witness whereof, I hereunto subscribe my name this 12th day of November, A. D. 1909.

FRANCIS A. WINSLOW.

Witnesses ARTHUR H. Bonr'rcrrnn, ALBERT C. BELL. 

